Trigger lock for pistols



Jan. 25, v Y J, QUINN ETAL- TRIGGER LOOK FOR PISTOLS Filed Dec. 2, 1947 INVENTORS N JOHN OUl/VA/ LAWRENCE LJWGDON/f v BY I fi w-fl ATTORNEY Patented Jan. 25, 1949 TRIGGER LOCK FOR PISTOLS John Quinn, Washington, D. (2., and Lawrence L. McDonie, Coral Hills, Md.

Application December 2, 1947, Serial No. 789,262

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 4 Claims.

This invention relates to improvements in trigger locks for firearms, a specialized use thereof being in conjunction with automatic pistols although its principles could be employed in trigger locks for weapons of types other than pistols. For the purposes of this disclosure, the trigger lock is illustrated on what is known to persons familiar with small arms as the Colt automatic pistol, caliber .45, M1911 and M1911A1, the standard and current type of which has been responsible for serious accidents at times, due to the lack of a safeguard against the possibility of discharge of a cartridge occupying the bore in the absence of the magazine.

The presence of said cartridge can be the result of any of several contingencies. First, the user of the pistol may fail fully to count or may miscount the firing of the cartridges, thereupon to remove the magazine and omit to insert a refill, all the while being unaware of the possibility of there being a cartridge in the chamber of the barrel. Second, in the event of desiring to fire more than the magazine limit of seven cartridges at one loading, the slide is drawn back, a cartridge is inserted in the chamber of the barrel and the slide is allowed to close, but some distrac ion may divert the user from inserting the magazine and cause him to forget that the pistol is loaded and in condition to be fired. Third; a pistol subject to repairs may contain a jammed cartridge which could be fired by an inadvertent pulling of the trigger. Each of these cases is distinguished by the absence of a magazine from the magazine chamber, leading to a false sense of safety in handling the pistol.

As is readily understood from the foregoing premise, the supposedly unloaded pistol can be fired because there is no provision for locking the trigger in the absence of a magazine in the receiver. The latter circumstance might lead a person either holding or picking up the pistol to think that it were not loaded, thus prompting him to handle and accidentally to fire the pistol with the consequences already mentioned.

Therefore, it is proposed to equip the pistol with a safety device which automatically locks the trigger in its forwarded, i. e. safe position when the magazine is removed from the receiver. In addition to this facility, the invention has the important advantage of ready embodiment in the standard pistol identifled'above, with but a minimum of modification so that the cost involved in said modification, or the henceforth original manufacture of pistols embodying the improvement, is confined to a small and inconsequential amount. The safety device weighs less than one ounce.

From these general statements it will be understood that one of the objects of the invention is to promote safety'in the use of automatic types of small arms by automatically locking the trigger against manual operation whenever the magazinc is removed.

Another object of the invention is to limit the requirement of modification of the particular type of pistol herein contemplated, or its equivalents, to a minimum of work and material.

Another object of the invention is to locate the trigger lock at a place of virtually immediate access, namely, against the left outer surface of the receiver and beneath the left stock or cover plate, so that the removal of the two stock or cover plate screws is the only requirement for reaching the single Working part for its replacement in the event of a breakage, especially in the field.

Another object of the invention, and one influencing the adoption of the aforesaid location, is the emplacement of the lock on an external part of the receiver, thereby to avoid the necessity of involving the intricateinternal mechanism in any manner, and with an important assurance, in the event of a breakage, against any of the .pieces getting into said mechanism and jamming the pistol.

Other objects and advantages will appear in the following specification, reference being made to the accompanying drawings, in which:

Fig. 1 is a side elevation of a pistol, a portion of the left stock or cover plate being broken away to illustrate the emplacement of the trigger lock against the left and external surface of the receiver; v

Fig. 2 is a vertical section taken substantially on the line 2-2 of Fig. 1, parts being shown in elevation, the trigger lock being displaced by the magazine;

Fig. 3 is a similar sectional view, illustrating the functioning of the trigger lock in'the absence of the magazine;

Fig. 4 is a fractional perspective view of the grip portion of the pistol receiver, a part thereof being broken away;

Fig. 5 is a perspective view of the leaf spring which constitutes one of the important elements of the invention; and 1 Fig. 6 is a perspective view of the left stock or cover plate of the receiver.

Some of the characteristics of the known pistol l0 will be'recognized as comprising the barrel H,

recoil-operated slide i2, the hammer IS, the receiver it, the left and right stocks or cover it and it, the magazine I! and the trigger it. The trigger bar H! which is integral with the trigger, and which has the form of a rectangular loop (Fig. 4), is guided by the walls of parallel slots 2:? in the confronting inner surfaces 2 of the receiver. The lateral depth of the slots and the thickness of the longitudinal members of the trigger bar are practically the same, so that they lie flush with the surfaces 2 I.

Openings 22 in the sidesv of the receiver M expose side portions of the magazine I?! when the latter is in place. The upper extremity of the standard magazine has inturned'lips2 3wliich, in part, outlin an orifice at the front of which the cartridges emerge. In addition to their function of retaining the cartridges until they are pushed out, one or the other of the two lips acts as a cam to release the trigger lock in the manner presently explained.

Lower and upper pairs of bushings 24 and 25 provide the mounts for the stocks F and i6. Onlythe lower bus-hing 25 on the left side enters into consideration herein, since the trigger lock is located on said side. It could be located on the right side. It is not required on both sides. Each of the bushings has a collar such as '26 on the lower left bushing, for the purpose of limiting the screwing of the bushings into the receiver. Screw 2:? driven into the bushings secure the cover plates wh'en empl-aced on the bushings as shown. The inner races of the cover plates are rahbetedsat '28, usually for the purpose of conserving material. The 'rabbet in the left cover plate provides a convenient pocket in which the trigger lock is recessed for the major part of its length.

.lih'omzithis point-on the description is addressed to. the details-of the. invention, the main element of which consists of the leaf spring 29. This spring' comprises ailength of resilient metal'which is; formed with an initial bow as illustrated-'- in Fi -i .At its. lower end it has a hole fill which ic -large enough tcfltpfreelyupon the collar 26: of the: low-erleft bushing 214 The bushing collar thusservesaswthe lower mount'ior the leaf spring.

.Atits upper end: the leafspring has locking and-cam pins 3i and 3.4.; They are spaced lon=- gitudinally of the leaf spring and are attached by riyeting. The upperpin. illwhich is the shorter of the- :two, occupies: the component 3'3 of a hole in -thelreceiuer ItSi-bEVGIS'd free end Misadapted to enter a. complemental hole. component 3,5 in the adjacent longitudinal member Qf the trigger bar 13 when registration of the hole components occurs in. the. forward: or armed position of the trigger is. The hole 33, .315 is-ran element, of the invention. and Jisrdrilled through they partsnamed while thetrig-ger is imthe armed position. They locking 101. the; trigger resulting from the projection of pin 3| into hole- 325: nap-.- penswonly when the magazinel5! is. absent from the magazine chamber forassumes a position therein sufliciently far below the-cam pin 3%(Fig; 1%)- notto -displace itrromsaidachamloer.

From. this; it will; he: seen that. thepi-n .34 and its occupancy of the hole 33 provides. the upper mount for. the leaf; spring; The, latter i laid loosely against the left exterior: of the receiver Hi, being mounted upon the collar; Zfiancl held in line by the insertion-- of the pin, 3-1 inthe hole The cam pin 32 extends; into the adjacent cpeniig The .leftstock; or cover plate- ;t-E has s. recess shaped: torcceiwethelower extremity of the leaf spring, and to fully contain that part of the leaf spring when the cover plate is clamped in place by the two cover plate screws against the side of the receiver.

Upon clamping the cover plate 15 down by the driving .home of the screws 21', the initial bow (Fig. 5) in the spring E9 is eilaccd (Fig. 3) by the pressure of the bottom of the recess 38 against the spring. Thus the cover plate and its securement to the receiver are used as the means whereby the inherently loose lock spring is clamped in place. This assembly is while the magazine chamber is empty, the trigger it be ing in the forward or armed position which it normally assumes because of a spring (not shown) behindit. The spring being straightened, exerts an inward pressure which keeps it lying against the receiver, its upper pin (it in locking engagement with the trigger bar and its cam pin 32 pro-- iected past the opening 22 into the magazine chamber.

This relationship is maintained as long as the magazine chamber remains empty. The trigger [it cannot be pulled because its bar it is locked by the lock pin 3i. Upon inserting either a loaded or empty magazine ll into the chamber, the left lip 23 rides over the pin 32 (Fig. 2). The resulting cam action flexes the spring 29 outwardly, displacing the locking pin ill from the hole in the trigger bar and releasing, that is unlocking, the trigger 18 for action.

In equipping a pistol with the invention, whether to modify current pistols or to embody it in newly manufactured ones, a jig will be used for the accurate location of the holes 33 and The bushings 2 3, =25 on the left side of the receiver are .used as anchor points for the jig through which the drill is guided to center the holes on the vertical dimension of the nearest member of the trigger bar with the trigger in the armed position.

This drilling of the receiver and trigger bar is accomplished after the mere laying aside of the left cover plate t5. The pistol need not be disassembled. None of the existing mechanism is afiectcd otherwise than by the drilling of the one small hole simultaneously through the two parts. Access had from the exterior, and should a breaking of the spring 25) occur, none of the: pieces can fall into the mechanism to jam the pistol. Such a breaking cannot render the pistol useless or even temporarily inoperative. The lower, end remains clamped under the left stock. The upper end would be supported by engagement of the lock pin with the rabbet in the stock and the hole in the receiver. Should there be any loose pieces they will fall out when the magazine "is removed.

In the caseof the foregoing breakage, it is only the trigger lock that will have been disabled. A repairiseasily made by simply removing thetwo left screws 2'? and the left cover plate. whereupon a new safety device is loosely laid in place. Oneof its attachments is its mount on the lower bushing, the other mount being the engagement of its lock pin 32 with the wall of the holeinv the receiver. The two mounts keep the lock spring-in a permanent and established line from which it cannot deviate excepting by the foregoing remote chance of breakage.

The immunity of the pistol from damage due the breakage of the trigger lock is in marked contrast with the potentialities of known devices 0.11- x. 'aine purpose.- A review of the art most pertinent to the instant invention will disclose a rather wide variety of locks which (1) require more or less extensive alteration or special construction of the parts with which the lock is concerned, (2) additionally require special construction of the lock itself and (3) are so situated in' the internal workings of the weapon as to virtually make certain that jamming due to the lodgement of the parts ".inthe mechanism would result from a breakage;

The-invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

We claim:

1. In a firearm equipped with a trigger bar slidable in a receiver having a magazine chamber and having a bushing projecting from an external surface of the receiver, said receiver having a hole registrable with a hole in the trigger bar in the armed position of the trigger, a cartridge magazine-operable trigger lock comprising .an initially bowed leaf spring loosely emplaced against said surface, having a hole in one end fitting the bushing to provide one mount and having a locking pin at the other end occupying the receiver hole to provide acomplemental mount, a stock clamped against the receiver, being set upon the bushing and over the-contiguous part of the spring to efface its bow thereby to stress the spring and cause it to project the locking pin into the trigger bar hole, and a cam pin on the spring then extending into the necessarily vacant magaizne chamber.

2. In a firearm equipped with a trigger bar slidable in a receiver having a magazine chamher and having a bushing projecting from an external surface of the receiver, a cartridge magazine-operable trigger lock comprising a leaf spring having a hole in one end and a locking pin at the other end, said leaf spring being sup ported in an undeviating postion yet with inherent looseness by emplacement of the holed end over the bushing and the locking pin in the receiver-component of a hole transfixing the receiver and the trigger bar, a stock clamped against the receiver and spring to suspend its looseness and efface its bow thereby to hold it under pressure to project the locking pin into the trigger bar hole in the absence of a magazine from the chamber, and a cam pin on the spring then permissibly extendin into the chamber.

3. In a firearm having a cartridge receiver magazine chamber and a trigger bar slidable in the receiver, a trigger lock and means providing its mounting on an external and readily accessible surface of the receiver, said means comprising at least one screw bushing extending from the lower portion of said surface and ineluding a hole with components in the upper portion of the receiver and in longitudinal member of the trigger bar, said trigger lock comprising an initially bowed, inherently loose and separable spring having a hole in one end occupied by the bushing and providing one mount of a two-point attachment and at its other end having a lock pin engaging the wall of the receiver hole-component providing the other mount, and a stock fited on and secured to the bushing, being rabbeted to accommodate most of the spring and recessed to receive its lower portion, the securement of the stock clamping the spring against the receiver and effacing its bow to project the lock pin through the trigger bar hole-component, and a cam pin extending from the spring into the chamber in the. path of an insertible magazine.

4. In a firearm having a cover plate, a holding bushing therefor, a spring constituting a component of a trigger lock for use in said firearm, said spring comprising a leaf having a hole in one end to fit upon the bushing, and a pair of spaced pins at the other end of the spring, one pin being longer than the other pin to serve respectively as a cam actuable by an insertable and removable magazine and as a trigger lock.

JOHN QUINN. LAWRENCE L. McDONIE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1.089.195 Falco Mar. 3, 1914 

